1. Field of the Invention
This invention relates to a portable electronic device used for personal navigation.
2. Summary of the Background Information
A modern smartphone is typically provided with a conventional GPS receivers and with a transceiver for sending and receiving radio-frequency signals through an access point that sends and receives data over the Internet. It is known that a conventional GPS receiver does not function properly in many indoor areas because of the attenuation of satellite signals by the walls and roofs of structures and because many elements within buildings cause reflections of the satellite signals. While the conventional GPS system was not designed for use in indoor areas, a number of current attempts to modify the GPS system to provide indoor capabilities are now being made.
It is additionally known that WiFi signals from access points presently located within many buildings can be used to locate a modern smartphone at an accuracy within 2.5 meters, and that the internal compass and accelerometers within a conventional smart phone can additionally used to generate location data. Positioning data to be used in developing a mobile app for use within a specific indoor environment can now be generated by a server from data generated in the actual indoor environment with a smartphone receiving WiFi signals received therein.
A modern smartphone is typically provided with a camera, and many users of smartphones have downloaded an app for reading QR codes (a trademark taken from “quick response”), which are of a particular type of matrix (two-dimensional) bar code, originally used to track vehicles during assembly, and now widely used for advertising purposes. Such an app contacts the Internet through the communication capabilities of the smartphone and connects the smartphone with a web site identified by data stored within a QR code that has been photographed using the camera within the smartphone. For example, a QR code placed near a product displayed within a retail store may be used to connect the smartphone with a website providing additional information about the product including video demonstrations, etc.
RFID (radio frequency identification) tags have also been used to provide indoor, as well as outdoor, location information. For example, a visitor to a museum may be given a portable device including an RFID reader and an audio player having a number of stored audio messages describing exhibits within the museum, each of which is played when the portable device is brought into proximity with an RFID tag identifying the corresponding exhibit. Alternatively, the portable device is provided with communications capabilities allowing a server to be connected, with the server then providing audio and/or video information describing the exhibit identified by the RFID tag.